1. Field of the Invention
The present invention relates to a method of inspecting a substrate and an apparatus for performing the same. More particularly, the present invention relates to a method of inspecting a substrate to detect defects in the substrate, such as a silicon wafer, and an apparatus for performing the same.
2. Description of the Related Art
A semiconductor device, in general, is manufactured by performing a fabrication process for forming electric circuits on a semiconductor substrate such as a silicon wafer, an electrical die sorting process for inspecting electric characteristics of the electric circuits formed on the semiconductor substrate, a packaging process for packaging semiconductor devices formed on the semiconductor substrate in epoxy resins and individuating the semiconductor devices.
The fabrication process includes a deposition process for forming a layer on the semiconductor substrate, a chemical mechanical polishing process for planarizing the layer, a photolithography process for forming a photoresist pattern on the layer, an etching process for forming the layer into patterns having electrical characteristics using the photoresist pattern, an ion implantation process for implanting ions into specific regions of the semiconductor substrate, a cleaning process for removing impurities from the semiconductor substrate, a drying process for drying the cleaned semiconductor substrate, an inspection process for inspecting defects of the layer or patterns, and the likes.
Semiconductor devices are manufactured by repeatedly performing the unit processes as described above, and semiconductor substrates are received in a container such as a cassette and a front opening unified pod (FOUP) and transferred between processing apparatuses for performing the unit processes. Further, each of the semiconductor substrates is transferred between the container and the processing apparatuses.
The semiconductor substrates are damaged while transferring the semiconductor substrates. For example, defects such as scratches at a surface of the semiconductor substrate, a chipping at an edge portion of the semiconductor substrate, etc., are frequently occurred. The defects are detected during the inspection process. For example, the defects occurred at the surface of the semiconductor substrate are detected by a dark field inspection apparatus using scattering of laser beam, a bright field inspection apparatus using a charge coupled device (CCD) image sensor, and the likes.
However, defects, such as cracks, occurred in the semiconductor substrate cannot be detected by the inspection apparatuses. The cracks in the semiconductor substrate may be propagated, thereby causing breakage of the semiconductor substrate. Further, due to the unexpected breakage of the semiconductor substrate, the manufacturing process of semiconductor device may be interrupted and the apparatuses may also be contaminated.